# Learn the Basics ## BPMN and SpiffWorkflow Business Process Model and Notation (BPMN) is a diagramming language for specifying business processes. BPMN links the realms of business and IT, and creates a common process language that can be shared between the two. BPMN describes details of process behaviors efficiently in a diagram. The meaning is precise enough to describe the technical details that control process execution in an automation engine. SpiffWorkflow allows you to create code to directly execute a BPMN diagram. When using SpiffWorkflow, a client can create the BPMN diagram and still have their product work without a need for you to edit the Python code, improving response and turnaround time. ## BPMN Elements BPMN (Business Process Model and Notation) elements are the building blocks used to model business processes visually. They represent different aspects of a process, such as tasks, events, gateways, and flows, and are used to describe the flow of activities, decisions, and data within a process. ### Events Events, represented with circles, describe something that happens during the course of a process. There are three main events within business process modeling: start events, intermediate events, and end events. | **Event** | **Symbol**| **Description** | |-----------|-----------|-----------------| | Start Event |![Untitled](images/Start.png) | Signals the first step of a process | | Intermediate Event | ![Untitled](images/Intermediate.png) | Represents any event that occurs between a start and end event. | | End event | ![Untitled](images/End.png) | Signals the final step in a process. | ### Gateways Gateways represent decision points in a process. They determine which path the process will take based on certain conditions or rules. There are different types of gateways: | **Gateway** | **Symbol**| **Description** | |---------------|-----------|-----------------| | Exclusive gateway |![Untitled](images/Exclusive.png) | Evaluates the state of the business process and, based on the condition, breaks the flow into one or more mutually exclusive paths | | Event-based gateway | ![Untitled](images/Eventbased.png) | An event-based gateway is similar to an exclusive gateway both involve one path in the flow. In the case of an event-based gateway, however, you evaluate which event has occurred, not which condition has been met. | | Inclusive gateway | ![Untitled](images/Inclusive.png) | An inclusive gateway breaks the process flow into one or more flows. | | Complex gateway | ![Untitled](images/Complex.png) | Complex gateways are only used for the most complex flows in the business process. They use words in place of symbols and, therefore, require more descriptive text. | ### Tasks Tasks represent activities or work that needs to be performed as part of a process. They can be manual tasks that require human intervention or automated tasks that are executed by systems or applications. | **Task** | **Symbol** | **Description** | |---------------|------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Service |
![Untitled](images/Service_task.png) | Task that uses a Web service, an automated application, or other kinds of service in completing the task. | | Send |![Untitled](images/Send.png) | Task that sends a Message to another pool. The Task is completed once the Message has been sent. | | Receive | ![Untitled](images/Receive.png) | A Receive Task indicates that the process has to wait for a message to arrive in order to continue. The Task is completed once the| message has received. | | User | ![Untitled](images/User.png) | A User Task represents that a human performer performs the Task with the use of a software application. | | Manual | ![Untitled](images/Manual.png) | A Manual Task is a Task that is performed without the aid of any business process execution engine or any application. | | Business Rule |![Untitled](images/Businessrule.png)| Business Rule Task provides a mechanism for a process to provide input to a Business Rules Engine and then obtain the output provided by the Business Rules Engine. | | Script | ![Untitled](images/Script.png) | A Script Task defines a script that the engine can interpret. | | Call Activity | ![Untitled](images/Callactivity.png) | A call activity allows you to call and invoke another process as part of this process.processes. | | Sub-Process | ![Untitled](images/SubProcess.png) | Sub-processes allow you to collapse and expand tasks to quickly convey information. | ### Artifacts Artifacts are used to provide additional information or documentation within a process. They include data objects (representing information or data needed for the process), annotations (providing explanatory or descriptive text), and groups (used to visually group related elements). | **Artifact** | **Symbol** | **Description** | |---------------|------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Data Object |
![Untitled](images/Data_Object.png) | Data objects can represent data placed to the process, data resulting from the process, data that needs to be collected | | Data Storage |![Untitled](images/Data_Storage.png) | Data storage provides the ability to store or access data that is associated with a business model. If your process outputs any data, it will become necessary to store that data. | | Group |
![Untitled](images/Group.png) | Groups organize tasks or processes that have significance in the overall process.​​ | | Annotation |
![Untitled](images/Annotation.png) | Annotations allow you to describe the business process and flow objects in more detail. |